The personal flight logs of the co-pilot of the U.S. warplane that dropped the atomic bomb on Hiroshima 70 years ago didn't sell at an auction of World War II artifacts and memorabilia.

Bonhams in Manhattan says bidding Wednesday for the two log books belonging to Enola Gay co-pilot Capt. Robert Lewis didn't meet the reserve price.

Lewis, who died in 1983, filled the logs with his handwritten entries detailing every flight he made while in the Army Air Forces during World War II. They were part of an extensive archive of his wartime archive handed down to his son, Steven Lewis of New Jersey.

The entry for the Aug. 6, 1945, flight to drop the atomic bomb on Hiroshima reads: "No#1 Atomic bomb a huge success."

The presale estimate for the flight logs was $150,000 to $200,000.